JPS6335964B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a heat-developable photosensitive material,
In particular, it relates to a heat-developable photosensitive material that provides sharp images. A heat-developable photosensitive material having a heat-developable photosensitive layer containing at least (a) an organic silver salt, (b) a photocatalyst, and (c) a reducing agent is disclosed in, for example, U.S. Pat. It is publicly known. This heat-developable photosensitive material is said to have excellent gradation and high sensitivity compared to other dry processing photography methods, such as electrophotography, diazo photography, bubble photography, or thermography that utilizes the color reaction of leuco dyes. has advantages. The heat-developable photosensitive material is image-wise exposed to give the photocatalyst the ability to catalyze the oxidation-reduction reaction between the organic silver salt and the reducing agent under heating, and then heated (usually at 80°C or higher, preferably at 12°C).
℃ or higher) to improve the quality of the image. In this photosensitive system, only a small amount of the photocatalyst with photosensitivity is used, so even if it is left to change color due to light without any special fixing or stabilizing treatment after development, it is visually visible. is hardly a hindrance. However, one of the drawbacks of such heat-developable photosensitive materials is that images become blurred due to halation. In conventional wet-processed silver halide emulsion photographic materials, this problem is solved by providing an antihalation layer on the back of the support or between the support and the emulsion layer, which is decolorized or peeled off by liquid treatment after exposure. There is. However, one of the features of heat-developable photosensitive materials is that the only processing required is heating, so antihalation layers that are decolorized or peeled off by liquid processing are difficult to use in heat-developable photosensitive materials. Therefore, in order to prevent halation in a heat-developable photosensitive material, it is necessary to have an anti-halation layer that can be dry decolorized or changed to a color that does not interfere with the observation of the final image, or that can be peeled off.
The methods that have been proposed so far include a method using a mechanically strippable colored layer as an antihalation layer, as described in Japanese Patent Publication No. 48-33692, and a U.S. patent. No. 3769019, No. 4033948, No. 4033948, No.
4088497, 4153463, 3821001, and JP-A-54-56818, a method of using a colored layer containing a dye that decolorizes with heat as an antihalation layer, especially A method of using a colored layer containing an o-nitro-arylidene dye or an o-nitro-o-azaarylidene dye as an antihalation layer, as described in Japanese Patent Publication No. 54-17833, etc. There is. However, this method requires extra processing equipment just for the purpose of removing the antihalation layer and may damage the support during stripping, so it is not a very effective means. On the other hand, method (2) may cause decolorization during storage before processing depending on the temperature conditions, or may introduce excessive thermal fog. Furthermore, since the method requires a large amount of sub-rays for decoloring, there is a possibility that photodiscoloration may occur in the heat-developable photosensitive layer, and since a special dye is used, it is difficult to synthesize the dye and select a dye with the desired absorption wavelength. There were some problems, such as difficulty. The biggest drawback of the method (and) is that it takes a long time to decolorize the antihalation layer, or in other words, the speed of decolorizing the antihalation layer is slow. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photothermographic material having an antihalation layer that exhibits rapid decolorization or color change. Another object of the present invention is to be extremely stable during storage before processing, but when necessary, to easily change the coloring to a hue that is not inconvenient for image observation without causing thermal fogging or photodiscoloration to the heat-developable photosensitive layer. It is an object of the present invention to provide a heat-developable photosensitive material having a high image sharpness and having an antihalation layer that can be changed in color. Yet another object of the present invention is to enable the selection of dyes from a wide range to provide the antihalation layer with absorption characteristics at desired wavelengths. The present invention that achieves these objects has the following technical configuration. That is, the present invention provides at least (a) an organic silver salt, (b)
In a heat-developable photosensitive material having a heat-developable photosensitive layer containing a photocatalyst and (c) a reducing agent, and an anti-halation layer provided on the side of the heat-developable photo-sensitive layer opposite to the side to which the image is exposed, the anti-halation layer is provided. The layer is (d)
Contains a photosensitive halogen-containing compound that photodecomposes to lower the pH of the antihalation layer, and (e) is colored with a dye that causes a change in hue when the pH of the antihalation layer decreases. This is a heat-developable photosensitive material characterized by: The photosensitive halogen-containing compound of component (d), which is one element of the coloring composition used in the antihalation layer of the present invention, is an organic compound that decomposes upon irradiation with light and releases halogen radicals or hydrohalic acid. be. Such compounds are described, for example, in U.S. Pat.
3902903, British Patent No. 1432138, Japanese Patent Application Laid-open No. 120328/1983, No. 50-119624, 55-24113
Many compounds are known, such as those disclosed in Japanese Patent Publication No. 2003-100000, and in the present invention, an appropriate selection from such known photosensitive halogen-containing compounds can be employed as the component (d). Typical examples of photosensitive halogen-containing compounds that can be used as component (d) of the present invention include the following compounds. 1 A compound represented by the following general formula (). In the formula, X represents a halogen atom. R ₁ , R ₂ ,
R ₃ may be the same or different, and each R 3 is a hydrogen atom,
Halogen atom, nitro group, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, 2 carbon atoms
~11 alkylcarbonyl group, arylcarbonyl group having 7 to 15 carbon atoms, amide group substituted with an alkyl group having 1 to 10 carbon atoms, or aryl group having 6 to 14 carbon atoms, or an alkyl group having 1 to 10 carbon atoms or carbon A sulfonate group substituted with 6 to 14 aryl groups (alkyl groups or aryl groups in these groups can further include halogen atoms, hydroxy groups, nitro groups, alkyl groups, aryl groups, alkoxy groups, carbamate groups, carbonate groups,
(optionally substituted with a sulfonate group or a carboxylate group). R ₁ and R ₂ may be combined with each other to form a cycloalkyl ring. More specifically, the compounds included in the general formula () include carbon tetrabromide, tetrabromobutane, hexabromocyclohexane, α-chloro-p-nitrotoluene, iodoform, hexabromoethane, benzotrichloride, α- Bromo-p-nitrotoluene, α-bromo-m-
Nitrotoluene, α,α′-dichloro-o-xylene, α,α′-dibromo-p-xylene, α,
In addition to α, α′, α′-tetrabromo xylene, tribromoethyl cinnamate, etc., the formula:

A compound represented by the formula [where R ₄ represents an alkyl group or an aryl group, R ₅ represents a hydroxy group, an alkoxy group, a carbamate group, a carbonate group, a sulfonate group, a phosphate group or a carboxylate group,
X represents a halogen atom. For example, 2, 2, 2
-tribromoethanol, 2,2,2-tribromoethylcyclohexanecarbamate, 2,2,
2-tribromoethylbenzene carbamate,
2,2,2-tribromoethylbenzoate,
2,2,2-tribromoethyl ethyl carbonate, 1,1,1-trichloropropanol-2,
2,2,2-trichloroethanol, 2,2-dibromo-2-chloro-1-phenylethanol,
2-Methyl-1,1,1-tribromo-2-propanol, bis(2,2,2-tribromoethoxy)cyphenylmethane, p-toluenesulfonyltribromoethyl urethane, 2,2,2-tribromoethyl stearate , 2,2,2-tribromoethyl furoate, bis(2,2,2-tribromoethyl)succinate, etc.], Formula:

A compound represented by the formula [where R ₆ is an amino group, an alkyl group having 1 to 10 carbon atoms,
Represents an aryl group having 6 to 14 carbon atoms, R ₇ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and 1 to 10 carbon atoms.
represents an acyl group, and X represents a halogen atom. For example, 2-bromoacetophenone, 2-bromo-2-phenylacetophenone, 2-bromo-1,3-diphenyl-1,3-propanedione, α-bromo-2,5-dimethoxyacetophenone , α-bromo-γ-nitro-β-phenylbutylophenone, α-iodo-γ-nitro-β-phenylbutylophenone, 2-bromo-p-phenylacetophenone, 2-chloro-p -phenylacetophenone, 2-bromo-p-bromoacetophenone, 1,3-dichloroacetone, 2,2'-dichloro-4-chloromethylcarbonamide-benzophenone, etc.], Formula:

A compound represented by the formula [where R ₈ represents an aryl group having 6 to 12 carbon atoms or a benzothiazole group, R ₉ and R ₁₀ may be the same or different, and each is a hydrogen atom, a halogen atom,
It represents an alkyl group having 1 to 5 carbon atoms or an amide group having 1 to 11 carbon atoms, and X represents a halogen atom. For example, 2-bromo-2-phenylsulfonylacetamide, 2-bromo-2-(p-tolylsulfonyl)acetamide, 2-tribromomethylsulfonylbenzothiazole, dibromomethylsulfonylbenzene, tribromomethylsulfonylbenzene, etc.], and formula:

Compound represented by the formula [where n and m represent integers of 1 to 5, R ₁₁ and R ₁₂ are OH,

【formula】

[Formula] or -SO ₂ -R' (where R' is an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms), and X represents a halogen atom.
For example, 2-bromo-2-nitro-1,3-propanediol, 1,3-dibenzoyloxy-2
-bromo-2-nitropropane, 2-bromo-2
- nitrotrimethylene bis(phenyl carbonate), etc.). 2. A compound represented by the following general formula (). In the formula, A represents a heterocycle which may have a substituent, and B ₁ , B ₂ and B ₃ represent atoms selected from a hydrogen atom, a chlorine atom and a bromine atom. However, at least one of B ₁ , B ₂ , and B ₃ is a chlorine atom or a bromine atom. Specific examples include ω, ω, ω-tribromoquinaldine, ω, ω-dibromoquinaldine, 2-
There are compounds described in US Pat. No. 3,902,903 such as ω,ω,ω-tribromomethyl-4-methylquinaldine and ω,ω-dichloromethylquinoline. 3. A compound represented by the following general formula (). In the formula, D is an alkyl group having 1 to 5 carbon atoms, which may be substituted with a halogen atom, or an alkyl group having 6 to 10 carbon atoms.
represents an aryl group, and n represents an integer of 1 to 3. Specifically, 2,4-bis(tribromomethyl)-6-methyltriazine, 2,4,6-tris(dibromomethyl)triazine, 2,4,
6-tris(tribromomethyl)triazine,
2,4,6-tris(trichloromethyl)triazine, 2,4-bis(trichloromethyl)-
Examples include 6-methyltriazine and 2,4-bis(trichloromethyl)-6-phenyltriazine. 4. A compound represented by the following general formula (). In the formula, W represents a substituted or terminally substituted phenyl group or an unsubstituted naphthyl group, and the phenyl group is a halogen atom, a nitro group, a cyano group,
It has an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 4 carbon atoms as a substituent. Furthermore, the phenyl group has a structure in which two alkoxy groups form a ring.

It may take the form of [Formula]. The number of substituents is one or two in the case of a halogen atom, but one in the other cases. X
represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group. Y represents a halogen atom, n
represents an integer from 1 to 3. Specific examples include the following compounds described in JP-A-55-24113. The amount of these photosensitive halogen-containing compounds used is
When these photosensitive halogen-containing compounds are irradiated with absorbed light, the halogen radicals or hydrohalic acid generated by photolysis are sufficient to cause a change in hue in the dye of component (e). It is necessary that the amount is sufficient to lower the pH. However, it is generally convenient to combine the dye of component (e) and the photosensitive halogen-containing compound of component (d) in various ratios and irradiate them with light to determine the optimum amount to be used. Usually, 0.1 mol to 1 mol of component (d) is added to 1 mol of component (e).
When used in an amount of 100 mol, preferably in the range of 0.5 mol to 10 mol, it is possible to lower the pH of the above-mentioned antihalation layer to a necessary degree and cause a change in hue of the dye of component (e). The dye of component (e) used in the present invention has absorption in the photosensitive wavelength range of the heat-developable photosensitive layer in a normal state before being thermally developed, but when the pH of the antihalation layer decreases (i.e., the component (e) When d) is photodecomposed, its maximum absorption wavelength shifts to shorter or longer wavelengths, resulting in a change in hue. As component (e), one is selected so that the change in hue does not cause any inconvenience to image observation, in other words, one that gives the processed photosensitive material a desired hue. The desirable hue after processing is colorless;
There are pale colors and blue colors, but colorless colors are particularly preferred. Therefore, as component (e), the hydrohalic acid released by the photolysis of component (d) causes its base side absorption to shift to a shorter wavelength, and the maximum absorption wavelength shifts to outside the visible range, resulting in a colorless or colorless product. It is desirable to have a color that appears pale in color or a color that causes long wavelength shift so that it appears blue. Specifically, a compound represented by the following general formula () or () is used. Here, Z ₁ to _{Z 5} may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group,
-CH=N-OH group, carboxyl group, sulfo group,
Alkyl group (preferably up to 20 carbon atoms),
Acyl group (preferably up to 20 carbon atoms), alkoxy group (preferably up to 20 carbon atoms),
Amide group (preferably up to 20 carbon atoms), carbamoyl group (preferably up to 20 carbon atoms),
Sulfonyl group (preferably up to 20 carbon atoms),
It represents a sulfonamide group (preferably one having up to 20 carbon atoms), a sulfamoyl group (preferably one having up to 20 carbon atoms), an aryl group (preferably a phenyl group), and a nitro group. At least one of Z ₁ to _{Z 5} represents a nitro group. Z ₁ and Z ₂ and Z ₂ and Z ₃ may be bonded to each other to form a ring (such as a naphthalene ring or a quinoline ring, this ring may have the above-mentioned substituent). Specifically, (19) p-nitrophenol (20) 2-{2-(2,4-di-t-amylphenoxy)butanamide}-4-nitrophenol (21) 2,5-dinitrophenol (22) 2 , 6-di-t-butyl-4-nitrophenol (23) 8-hydroxy-5-nitroquinoline (24) 2-formyl-6-methoxy-4-nitrophenol Here, Z ₆ to _{Z 10} represent atoms or groups having the same range as listed in the general formula (), but at least one of Z ₆ to _{Z 10} does not need to be a nitro group. Instead, one of Z ₆ or Z ₈ is a phenylazo group

Represents [formula]. Here, Z ₁₁ to _{Z 15} represent atoms or groups having the same range as listed in the general formula (), but at least one of Z ₁₁ to _{Z 15} does not need to be a nitro group. Specifically, (25) 4-phenylazophenol (26) 4-(2-chlorophenylazo)phenol (27) 4-(3-chlorophenylazo)phenol (28) 4-(4-chlorophenylazo) ) Phenol (29) 4-(2,4-dichlorophenylazo)phenol (30) 4-(2,4,6-trichlorophenylazo)phenol (31) 3-chloro-4-(4-hydroxyphenyl) Enylazo)benzene-1-sulfonic acid Na salt (32) 2-(4-Hydroxyphenylazo)benzene-1-sulfonic acid Na salt (33) 4-(4-Hydroxyphenylazo)benzoic acid Na salt ( 34) 4-(4-carbamoylphenylazo)phenol (35) 4-(4-cyanophenylazo)phenol (36) 4-(2,6-dimethylphenylazo)phenol (37) 4-(2 -methoxyphenylazo)phenol (38) 4-(4-methoxyphenylazo)phenol (39) 2-carbamoyl-4-(2,4-dichlorophenylazo)phenol (40) 2-chloro-4- (3-sulfamoylphenylazo)phenol (41) 2-carbamoyl-4-(4-methoxyphenylazo)phenol (42) 2-chloro-4-(3-sulfamoylphenylazo)phenol ( 43) 2-chloro-4-(4-cyanophenylazo)phenol (44) 2-cyano-4-phenylazophenol (45) 5-acetyl-2,4-dihydroxyazobenzine (46) 4-( 2-chlorophenylazo)-2-nitrophenol (47) 3-methoxy-4-phenylazophenol (48) 2,4-dichloro-6-phenylazophenol (49) 4-phenylazonaphthol (50 ) 4-phenylazo-2-sulfamoylnaphthol (51) 5-methylsulfonamide-4-phenylazo-2-sulfamoylnaphthol (52) 2-carbamoyl-4-(4-methoxyethoxy-3-sulfonamide) Amoylphenylazo)naphthol (53) 4-(2,4-dichlorophenylazo)naphthol(54) 3-carbamoyl-1-(4-methoxyphenylazo)-2-naphthol(55) 3-(2 -Hydroxy-3-methoxyethylcarbamoylnaphtholazo)benzene-1
-sulfonic acid sodium salt (56) 2-(2-carbamoylphenylazo)naphthol-4-sulfonic acid sodium salt (57) 2-(2-chlorophenylazo)-4-methoxynaphthol (58) 2-(2 , 5-dimethyl-4-sulfamoylphenylazo)-4-nitronaphthol (59) 5-methylsulfonamide-4-(2-methylsulfonyl-4-nitrophenylazo)-naphthol (60) 4 -(4-Hydroxynaphthylazo)benzene-1-sulfonic acid Na salt All of these compounds are known and can be obtained commercially or by known synthetic methods. In the present invention, the above-mentioned component (e) is desirably in an amount sufficient to make the transmission optical density of the antihalation layer at least 0.1 or more, especially 0.3 or more, and the reflection optical density at least 0.05 or more, especially 0.1 or more. In order to maintain sufficient optical density with a limited amount of use, it is recommended to use completely dissociated products such as alkali metal salts or ammonium salts, or to use these salts in the presence of a cationic polymer mordant to increase the speed of decolorization. It is preferable because it is fast and the absorption of the basic example of the antihalation layer is shifted to the longer wavelength side. The cationic polymer mordant used in the present invention is a polymer containing a quaternary cation group and has a molecular weight of
5000-200000, especially 10000-50000. For example, US Patent No. 2548564, US Patent No. 2484430, US Patent No.
Vinylpyridinium cationic polymers disclosed in U.S. Pat. No. 3148061, U.S. Pat. crosslinkable polymeric mordants;
U.S. Patent No. 3958995, U.S. Patent No. 2721852, U.S. Patent No. 2798063,
JP-A-54-115228, JP-A No. 54-145529, JP-A No. 54-
Aqueous sol-type mordants disclosed in US Pat. No. 126027; water-insoluble mordants disclosed in US Pat. No. 3,898,088; US Pat.
No. 54-137333) Reactive mordant disclosed in the specification etc.;
Furthermore, U.S. Patent No. 3709690, U.S. Patent No. 3788855, U.S. Patent No.
No. 3642482, No. 3488706, No. 3557066, No. 3271147, No. 3271148, JP 50-71332
No. 53-30328, No. 52-155528, No. 53-125
Examples include mordants disclosed in No. 53-1024. Other examples include mordants described in US Pat. No. 2,675,316 and US Pat. No. 2,882,156. Among these mordants, those that are difficult to migrate from the antihalation layer to other layers within the photosensitive material layer are preferred, such as those that crosslink with the binder (matrix), water-insoluble mordants, and aqueous sol (or Latex dispersion) type mordants can be preferably used. Particularly preferred cationic polymer mordants are shown below. (1) A group having a quaternary ammonium group and capable of bonding with a binder (e.g., aldehyde group, chloroalkanoyl group, chloroalkyl group, vinylsulfonyl group, pyridiniumpropionyl group, vinylcarbonyl group, alkylsulfonoxy group, etc.)
For example, a polymer with (2) A reaction product of a copolymer consisting of a repeating unit of a monomer represented by the following general formula and a repeating unit of another ethylenically unsaturated monomer, and a crosslinking agent (eg, bisalkanesulfonate, bisarenesulfonate). R ₁ ; alkyl group, R ₂ ; alkyl group, aryl group, Q; divalent group, R ₃ , R ₄ , R ₅ ; alkyl group,
An aryl group or at least two of R ₃ to _{R 5} may be bonded to form a heterocycle. X: Anion (The above alkyl groups and aryl groups include substituted ones.) (3) Polymer represented by the following general formula x: about 0.25 to about 5 mol% y: about 0 to about 90 mol% z: about 10 to about 99 mol% A: Monomer having at least two ethylenically unsaturated bonds B: Copolymerizable ethylenically unsaturated Monomer Q: N, P R ₁ , R ₂ , R ₃ : alkyl group, cyclic hydrocarbon group,
Moreover, at least two of R ₁ to _{R 3} may be combined to form a ring. (These groups and rings may be substituted.) (4) Copolymer (a) consisting of (a), (b), and (c)

[Formula] or

[Silver behenate (contains 20 mol% free stearic acid) 76 g Polyvinyl butyral 80g Isopropyl alcohol 200g n-butyl acetate 200g]

The above composition was dispersed using a homogenizer to prepare a silver salt polymer dispersion. This silver salt polymer dispersion was maintained at 50° C., and the following solution was added and heated for 90 minutes to convert a portion of silver behenate into silver bromide. [N-bromosuccinimide 4g acetone 100ml] The silver behenate-silver bromide polymer dispersion thus prepared was kept at 40°C, and the following compounds were added in the order listed in 5.
A coating solution was prepared by adding at minute intervals. [(1) Sodium benzenethiosulfonate (0.05% by weight ethanol solution) 18ml (2) Phthalic acid (4% by weight ethanol solution) 25ml (3) 3,4-dichlorobenzoic acid (3% by weight ethanol solution) 25ml (4 ) Reducing agent of the following formula (16% by weight acetone solution) 140ml (5) Sensitizing dye (formula below) (0.1% by weight ethylene glycol monomethyl ether solution) 35ml (6) Phthalazinone (color toning agent) (6% by weight ethylene glycol monomethyl ether solution) 140ml (7) Hexamethylene diisocyanate (hardener) (1% by weight n-butyl acetate solution) 40ml] Coating solution prepared in this way The amount of silver per 1 m ² is based on polyethylene terephthalate film.
It was applied in an amount of 1.5g. Further, as an overcoat layer, a 2% by weight acetone solution of cellulose diacetate was provided in an amount of 0.5 g per 1 m ² of the polymer layer. The heat-developable photosensitive material thus prepared is hereinafter referred to as "Sensitive material A". On the other hand, an antihalation layer having the composition shown below was coated on the back side of the polyethylene terephthalate film base so that the concentration at the maximum absorption wavelength of each component (e) used was as shown in Table 1. Other than that, photosensitive materials B to K were prepared in exactly the same manner as photosensitive material A. [Cellulose diacetate 5g Poly-(tri-n-hexyl-vinylbenzylammonium chloride) 0.6g Ingredients of the present invention shown in Table 1 (d) Amounts shown in Table 1 Ingredients of the invention shown in Table 1 (e) Amount shown in Table 1 Acetone 61ml Ethylene glycol monomethyl ether
5 ml] The sensitive materials A to K were exposed to a light source mainly having a wavelength of 450 nm, and then developed by heating at 130° C. for 16 seconds. The wedge used was a strip wedge with a 100μ black gap. In the developed "Sensitive Material A", considerable blackening was observed even in the portion corresponding to the 100 μm black gap in the wedge, which was not supposed to be exposed. This can be considered to have been developed due to exposure to light reflected by halation. However, “Sensitive material B~
K” does not have this kind of blackening and has a sharp appearance.
A 100 μm unexposed thin line appeared (see Table 1). However, if left as is, the unexposed areas were colored and gave an ugly image quality. However, this “sensitive material B
~K'' was exposed to light using a 1 kW mercury lamp at the distances shown in Table 1 for the times shown in Table 1, the coloration easily became pale or colorless (see Table 1).Thus, according to the present invention, the sharpness It is highly preferable to have a high-quality image appear on a light to colorless background.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A heat-developable photosensitive layer containing at least (a) an organic silver salt, (b) a photocatalyst, and (c) a reducing agent, and a photothermally-developable layer provided on the side opposite to the image-exposed side of the photothermally-developable layer. In a heat-developable photosensitive material having an antihalation layer, the antihalation layer comprises (d) a photosensitive halogen compound that photodecomposes to lower the pH of the antihalation layer; and (e) the antihalation layer has a lower pH. Pigments represented by the following general formula () or () that sometimes cause a change in hue General formula () General formula () {In the formula, Z ₁ to _{Z 5} or Z ₆ to _{Z 10} may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a -CH=N-OH group, a carboxyl group, a sulfo group, Represents an alkyl group, an acyl group, an alkoxy group, an amide group, a carbamoyl group, a sulfonyl group, a sulfonamide group, a sulfamoyl group, an aryl group, and a nitro group. Z ₁ and Z ₂ , Z ₂ and Z ₃ , Z ₆ and
Z ₇ , Z ₇ and Z ₈ may be bonded to each other to form a ring. In general formula (V), at least one of Z ₁ to _{Z 5} represents a nitro group. In the general formula (), at least one of Z ₆ or Z ₈ represents a phenylazo group} and (f) a heat developable product characterized in that it is colored by a cationic polymer mordant that mordants the component (e). photosensitive material.